The mutability of language does not make the meaning of a text entirely arbitrary.

The date used as the end of the ancient era is entirely arbitrary.

This decision, if it were not to be entirely arbitrary, would presumably be based upon considerations of style or general policy.

Like all really good recipes, the proportion of one to the other is entirely arbitrary and you could use canned rather than fresh pineapple.

He lived so much within his own head that the times at which he ate and slept were entirely arbitrary.

I cannot be sure that some totally unsuspected force is not at work in some entirely arbitrary way.

A convenient, though entirely arbitrary, point to begin an account of recent changes in the English village is the middle of the nineteenth century.

The number of chapters is never entirely arbitrary.

The direction used in a writing system is entirely arbitrary and established by convention.

In this regulation, the usual legal approach has been swept aside for an entirely arbitrary one.